Urban expert Bruce Katz has noticed a change in how our world is structured. National states and governments no longer hold the central power to fix our modern world. Cities and metropolitan regions, he says, are now in charge of their own futures.

The reintroduction of wolves to Yellowstone was controversial when it happened in 1995, and it added more fuel to the blazing feud between conservationists and the ranchers and hunters who wish wolves had never returned to the Rockies.

For centuries, poets and philosophers extolled the benefits of a walk in the woods. The writer Florence Williams set out to learn if they were right. She discovered that time in nature is not just a luxury; it's actually essential to our humanity.